added count(predicate) helper function to String along with Char.is*() methods from java.lang.Character

libraries/stdlib/test/StringTest.kt

@@ -3,17 +3,17 @@ package test.string
 import kotlin.io.*
 import kotlin.test.*
 
-import junit.framework.*
+import org.junit.Test as test
 
-class StringTest() : TestCase() {
-    fun testStringIterator() {
+class StringTest {
+    test fun stringIterator() {
         var sum = 0
         for(c in "239")
             sum += (c.toInt() - '0'.toInt())
         assertTrue(sum == 14)
     }
 
-    fun testStringBuilderIterator() {
+    test fun stringBuilderIterator() {
         var sum = 0
         val sb = StringBuilder()
         for(c in "239")
@@ -26,7 +26,7 @@ class StringTest() : TestCase() {
         assertTrue(sum == 14)
     }
 
-    fun testOrEmpty() {
+    test fun orEmpty() {
         val s: String? = "hey"
         val ns: String? = null
 
@@ -34,16 +34,22 @@ class StringTest() : TestCase() {
         assertEquals("", ns.orEmpty())
     }
 
-    fun testToShort() {
+    test fun toShort() {
         assertEquals(77.toShort(), "77".toShort())
     }
 
-    fun testToInt() {
+    test fun toInt() {
         assertEquals(77, "77".toInt())
     }
 
-    fun testToLong() {
+    test fun toLong() {
         assertEquals(77.toLong(), "77".toLong())
     }
 
+    test fun count() {
+        val text = "hello there\tfoo\nbar"
+        val whitespaceCount = text.count { it.isWhitespace() }
+        assertEquals(3, whitespaceCount)
+    }
+
 }